ACACIA SEEDLINGS. 95 



they should be conveyed on pieces of driftwood or pumice, 

 for the very long distances, but anyone familiar with the 

 sea shore well knows that every flooded river carries vast 

 quantities of debris into the ocean, and some of this is 

 transported by currents far from its original home. 



Charles Darwin visited Oocos Keeling Islands in 1836, 

 and collected specimens of about twenty species of plants, 

 the whole of which he considered " must have been trans- 

 ported by the waves of the sea." The collection included 

 a specimen doubtfully identified as Acacia Farnesiana, 

 which species has since been definitely recorded for the 

 Islands. 1 Darwin also quotes from Holman's Travels to 

 the effect that amongst other things found washed up on 

 the Islands were "immense trees, of red and white cedar, 

 and the blue gum-wood of New Holland." 2 He subsequently 

 carried out a series of experiments to test how' long 

 various kinds of seeds would bear immersion in sea- water 

 without losing their vitality. 3 



In an exhaustive work on various Insular Floras of 

 the Atlantic, Pacific and Southern Oceans, W. Botting 

 Hemsley, f.r.s., discusses oceanic dispersal of plants and 

 quotes Professor Oh. Martins, of Montpellier, as having 

 germinated a seed of Acacia julibrissin, (Albizzia juli- 

 brissin according to Index Kewensis), and also of eight other 

 species of plants, after having immersed the seeds in sea- 

 water for ninety-three days. 4 He also quotes Alphonse 

 De Oandolle, and Gustave Thuret as considering that 

 oceanic currents, though effective in certain cases, exercise 

 extremely little influence in the diffusion of plants. 



1 Journal of Eesearches into the Geology and Natural History of the 

 Various Countries visited by H.M.S. Beagle, p. 541. 



2 Holman's Travels, Vol. iv, p. 378. 



3 Gardener's Chronicle, 1855, and Journ. Linn. Soc. Lond., i, p. 130. 



4 Report of the Scientific Eesults of the Voyage of H.M.S. Challenger, 

 Botany, Vol. i, p. 283. 



